Levofloxacin
Brand names: Levaquin
Class: 💊 Macrolides, Tetracyclines & Fluoroquinolones
On board day, levofloxacin is the respiratory fluoroquinolone with reliable atypical coverage and complicated-UTI activity. It inhibits DNA gyrase and topoisomerase IV and treats community-acquired pneumonia in patients with comorbidities, complicated UTI, acute pyelonephritis, prostatitis, and skin infections. Like ciprofloxacin, it carries multiple black boxes — tendon rupture, peripheral neuropathy, aortic aneurysm/dissection, CNS effects, and myasthenia gravis exacerbation — plus QT prolongation and C. difficile risk. Avoid in pregnancy and in children when alternatives exist. Use it for true respiratory indications in patients who cannot take amoxicillin, doxycycline, or a macrolide; do not reach for it for routine sinusitis or uncomplicated UTI on the exam.
✅ Indications
CAP (atypical coverage), complicated UTI, acute pyelonephritis, prostatitis, skin infections.
⚙️ Mechanism of Action
Fluoroquinolone — respiratory "gold" due to S. pneumoniae coverage.
📏 Dosing
500–750 mg PO/IV daily.
🚫 Contraindications
Children/adolescents, pregnancy, myasthenia gravis.
⚠️ Adverse Effects
Same FQ class warnings: tendon rupture, aortic dissection, peripheral neuropathy, QT, C. diff, hypoglycemia, seizures.
🔬 Monitoring
Clinical response; ECG if QT risk.
💎 Board Pearls
- 🫁 RESPIRATORY FLUOROQUINOLONE — covers S. pneumoniae (cipro does NOT well).
- ⚠️ Same black-box warnings as ciprofloxacin — reserve for when narrower-spectrum agents have failed.
- 👵 ↑ risk tendon rupture in >60 yr and steroid users.
Practice Questions
A 58-year-old man with a documented severe penicillin and macrolide allergy presents with fever, productive cough, pleuritic chest pain, and an RLL infiltrate on chest x-ray. He has COPD and was hospitalized for pneumonia 6 months ago, making atypical coverage (Mycoplasma, Legionella, Chlamydophila) and S. pneumoniae coverage essential. Which of the following is the most appropriate outpatient antibiotic?
Related Drugs in This Class
- Azithromycin — Zithromax, Z-Pak
- Doxycycline — Vibramycin, Doryx
- Ciprofloxacin — Cipro
Sources
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